Not sure if they have Kinder Surprise in North America, but they are little plastic eggs with a toy and chocolate inside. The toys are often little animals.
This egg slit yesterday morning and when I got home last night had clearly worked on the slit a bit more but was in no rush to come out. This photo was taken at 7:30 pm and by 11:00 pm had still not moved (my taking its photo probably didn't help).
I am disappointed that I hadn't photographed it a day or two before it hatched, for it had three huge dents running along the top, bottom and one of the sides, leaving what seemed like 50% of its volume for the hatchling. It popped back to normal shape once slit.


